This invention relates to a motor controlling switch device for controlling an electric motor which is used in a power window regulator, power sunroof, power curtain or the like of an automobile.
A power window regulator of an automobile is equipped with a switch device which includes a knob and a holding switch. The knob is situated in a casing so that a restoring force is applied to the knob at all times keeping it in its primary position. The knob is moved from the primary position to a first operating position by pushing it. The knob is turned from the first operating position to a second operating position by pushing it again. Thus, the knob is designed to operate in two steps. A motor operating switch is provided which is in the on position when the knob takes the first or second operating position. The first or second operating position completes the electric circuit for forward or reverse rotation of the motor, or vice versa depending upon the wiring arrangement selected, for opening or closing the window, depending upon the mechanical coupling arrangement between the motor and the window.
A holding switch also is provided which, when the knob is moved to the second operating position, is turned on to apply current to an electromagnetic solenoid adapted to attract and hold the knob at the second operating position. Therefore, when the knob is turned to the first operating position, the window glass is continuously moved to open or close the window as long as the knob is kept at the first operating position. When the knob is set at the second operating position, the window glass is moved until the window is fully opened or fully closed even if the knob is released. When the window has been fully opened or closed, the driving motor is stopped in locking manner.
In order to overcome this difficulty, heretofore, a detecting device is employed which is designed as follows. The detecting device, including a contactor to which direct current is applied, is brought into contact with a sector wheel which is coupled to a lever to directly move the window glass. The sector wheel is engaged with a pinion driven by the motor detecting circuit for detecting spike-shaped noises which are induced in the contactor as the contact resistance changes with movement of the sector wheel. A transistor is connected in series to the above-described electromagnetic solenoid, the transistor being turned on as long as the detecting circuit detects the noises. When the detecting circuit detects no noise, i.e., when the motor is stopped in locking manner with the window fully opened or closed, the transistor is turned off. Consequently, the current applied to the electromagnetic solenoid is turned off and the knob is returned to its original position to deenergize the motor. The detecting device is intricate in construction, and the power window regulator switch device is large in size, high in manufacturing cost, and requires a relatively large installation space.
In view of the foregoing, an objective of this invention is to provide a motor controlling switch device in which, when the motor is stopped in locking manner, an operating member adapted to operate a switch for applying current to the motor is returned from its operating position to its original position. The motor controlling switch is simple in arrangement, small in size and low in manufacturing cost and which can be installed in a small space.